Methods and instruments for subchondral treatment of osteoarthritis in a small joint

ABSTRACT

Devices, instruments and associated methods for the subchondral treatment of osteoarthritis in small joints are provided. In addition, a method for treating joint pain in small joints is provided. These small joints may be ankle, elbow or wrist joints. The methods may target one of many different access points having trajectories with a common focal point at or near the small joint. The instruments may limit access to areas within or near the small joint by providing predefined entry paths that avoid damage to surrounding tissues.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/649,415 filed Oct. 11, 2012, now issued as U.S. Pat. No. 9,168,100,which claims priority to U.S. Provisional No. 61/545,846 filed Oct. 11,2011 and entitled “Methods and Instruments for Subchondral Treatment ofOsteoarthritis in the Ankle Joint,” the content of each of which areincorporated by reference in its entirety.

FIELD

The present disclosure relates to devices and instruments for thesurgical treatment of osteoarthritis at or near a joint, and moreparticularly to devices, instruments and associated methods for thesubchondral treatment of osteoarthritis in a small joint, such as anankle, wrist, or elbow joint.

BACKGROUND

Human joints, in particular the knee, hip, shoulder, ankle, and spine,are susceptible to degeneration from disease, trauma, and long-termrepetitive use that eventually lead to pain. Joint pain arising fromosteoarthritis, for example, is the impetus for a wide majority ofmedical treatments and associated medical costs. The most popular theoryarising from the medical community is that joint pain results frombone-on-bone contact or inadequate cartilage cushioning. Theseconditions are believed to frequently result from the progression ofosteoarthritis, which is measured in terms of narrowing of the jointspace. Therefore, the severity of osteoarthritis is believed to be anindicator or precursor to joint pain. Most surgeons and medicalpractitioners thus base their treatments for pain relief on this theory.For example, the typical treatment is to administer pain medication, ormore drastically, to perform some type of joint resurfacing or jointreplacement surgery.

However, the severity of osteoarthritis, especially in joints such asthe knee and ankle, has been found to correlate poorly with theincidence and magnitude of the pain. Because of this, surgeons andmedical practitioners have struggled to deliver consistent, reliablepain relief to patients, especially if preservation of the joint isdesired.

Whether by external physical force, disease, or the natural agingprocess, structural damage to bone can cause injury, trauma,degeneration or erosion of otherwise healthy tissue. The resultantdamage can be characterized as a bone defect that can take the form of afissure, fracture, microfracture, lesion, edema, tumor, or sclerotichardening, for example. Particularly in joints, the damage may not belimited to a bone defect, and may also include cartilage loss(especially articular cartilage), tendon damage, and inflammation in thesurrounding area.

Patients most often seek treatment because of pain and deterioration ofquality of life attributed to the osteoarthritis. The goal of surgicaland non-surgical treatments for osteoarthritis is to reduce or eliminatepain and restore normal joint function. Both non-surgical and surgicaltreatments are currently available for joint repair.

The technique of subchondrally treating joints affected byosteoarthritis (OA) to relieve the associated pain, as well as treat theunderlying disease, has been previously described by applicants. Thissubchondral treatment involves the stabilization and/or stimulation ofthe subchondral space at the area of the joint damaged byosteoarthritis, while also preserving as much as possible the articularsurface of the joint. This subchondral treatment may be applied to alljoints of the human body, including smaller joints such as ankle, elbow,or wrist joints.

In some cases, the ease with which the subchondral treatment developedby applicants is administered depends in large part on theinstrumentation that is available to effect the treatment. One of thesetbacks of using currently available surgical access devices andinsertion tools is the lack of ability to target a specific area of thebone to be treated in a fast, accurate, easy and controlled manner.Presently, in order to treat or repair a bone defect at a joint, thesurgeon often has to take multiple steps using multiple surgical toolsin order to access, locate, and treat the target defect site. Even so,the surgeon does not have a reliable instrument or system that wouldallow him to easily and quickly target an area such as the subchondralregion of a joint, and either deliver to, or remove material from, thattarget region. In order to perform repeated or multiple procedures inthe same defect location with the currently available tools, additionaland unnecessary time in the operating room would be required, as well asan increased risk for complications since numerous instruments andmaneuvers are at play.

In the particular case of an ankle joint, the key bone is called thetalus, or astralagus, bone. This is a small bone that sits between theheel bone (calcaneus) and the two bones of the lower leg (tibia andfibula). The talus has an irregular, humped shape, similar to that of aturtle. The bones of the lower leg articulate on top and around thesides to form the ankle joint. Where the talus meets the bones of thefoot, it forms the subtalar joint, which is important for walking onuneven ground. Thus, the talus is an important connector between thefoot and the leg and body, helping to transfer weight and pressureforces across the ankle joint. It is also for this reason that the talusis susceptible to fracture and degradation from osteoarthritis.

Due to the uniquely curved shape of the talus, subchondral treatment ofthe ankle joint may be challenging. In particular, precise, controlledand repeatable targeting of the subchondral region of the talus bone maybe particularly difficult due to the inherent natural topography (i.e.,curvature) of the bone. Accordingly, it is desirable to provideinstruments that allow fast, easy, and controllable surgical access tothe target site, or the bone defect within these small joints, to betreated. Even more desirable are instruments that allow reliable,repeatable and precise targeting and navigation to the subchondraltarget area of these small joints, such as the ankle joint. Thus, whatare needed are instruments for subchondral treatment of small jointsthat accommodate their anatomy, and allow for treatment with ease,repeatability and accuracy.

SUMMARY

The present disclosure provides devices, instruments and associatedmethods for the subchondral treatment of joint pain and osteoarthritisof joints, and more specifically to instruments that allow fast, easy,precise, controllable and repeatable access to the subchondral bone of asmall joint having osteoarthritis. For example, the small joint may bean ankle, elbow or wrist joint. In particular, devices, instruments andassociated methods for the subchondral treatment of osteoarthritis insmall joints are provided. In addition, a method for treating joint painin small joints is provided. These small joints may be ankle, elbow orwrist joints. The methods may target one of many different access pointshaving trajectories intersecting at a common focal point at or near thesmall joint. The instruments may limit access to areas within or nearthe small joint by providing predefined entry paths that avoid damage tosurrounding tissues.

In one embodiment, a method for treating joint pain is provided. Themethod comprises: identifying a subchondral defect in a subchondralregion of a bone of a joint; providing a guide instrument having portalsrepresenting predefined trajectories for accessing an internal area ofthe bone, wherein at least one or more of the trajectory pathsintersects at a focal point; selecting a portal of the guide instrumentcorresponding to the selected subchondral access path; and treating thesubchondral defect, via the selected portal of the guide instrument,while preserving the articular surface of the bone. The subchondraldefect may be a bone marrow lesion, bone marrow edema, or insufficiencyfracture. The joint may be a small joint, such as for example an anklejoint, wrist joint, elbow joint, or even shoulder joint. Treatment ofthe subchondral defect may comprise injecting a bone hardening materialin the bone, or implanting a reinforcing member that stabilizes thesubchondral defect.

In another embodiment, a guide instrument for delivering an instrumentto a subchondral region of a joint is provided. The guide instrument maycomprise a guide frame comprising at least one opening for receiving afixation element; a detachable alignment bar connectable to the guideframe; and a guide ring comprising a plurality of openings for receivingtherethrough an instrument or tool to the subchondral region of thejoint, wherein each opening provides a predefined trajectory path intothe subchondral region, at least one or more of the trajectory pathsintersecting at a focal point. The guide instrument may be configuredfor use with a small joint, such as for example an ankle joint.

In yet another embodiment, a guide instrument for delivering aninstrument to a subchondral region of a joint is provided. The guideinstrument may comprise a main body having a generally wedge shape witha first end extending into a first flange and a second end extendinginto a second flange, each of said first and second flanges having oneor more openings for receiving an instrument for insertion into thesubchondral region of the joint to be treated, and wherein the openingsof the first flange are elongated slots. The guide instrument may beconfigured for use with a small joint, such as for example an anklejoint.

In still another embodiment, a guide instrument for accessing asubchondral region of a joint is provided. The guide instrument maycomprise a main body having one or more predefined angled portalsextending therethrough, a tab extending from the main body and having athrough-hole for attachment to a stabilizer, and an alignment armextending from the main body, the alignment arm being configured toallow fluoroscopic verification of the angulation of the guideinstrument with respect to an anatomical landmark. The guide instrumentmay be configured for use with a small joint, such as for example anankle joint.

In yet another embodiment, a foot stabilizer and guided accessinstrument is provided. The instrument comprises a platform having afastening element for securing to a foot; a track extending from theplatform; an attachment arm adjustably movable along the track; and aguided access component adjustably connected to the attachment arm, theaccess component including a main body having a rotatable hub from whichextends an access portal for guiding an instrument to a location on ornear the foot, and a visualization bar to align the guided accesscomponent to an anatomical marker of the foot.

In still yet another embodiment, a foot stabilizer and guided accessinstrument is provided. The instrument may comprise a platform having afastening element for securing to a foot, and a guided access componentadjustably connected to the fastening element, the access componentincluding a rotatable bar from which extends a pair of grid panels, eachgrid panel comprising a plurality of access portals for guiding aninstrument to a location on or near the foot, wherein the grid panelsfurther include visualization markers to align the panels relative tothe foot.

In even still another embodiment, an instrument for guided access to asubchondral area of a joint is provided. The instrument may comprise aprobe. The probe may have a handle extending into a guide body and abone rest, the guide body comprising a platform including one or moreportals for guided access of an instrument into a joint and beingdetachable from the handle, the bone rest being configured to restagainst a bone of the joint.

In still another embodiment, a foot stabilizer and guided accessinstrument is provided. The instrument comprises a platform connected toa boot for receiving a foot therein, the boot comprising a plurality ofaccess portals for the insertion of an instrument therethrough, theinstrument being formed of a material for visualization during magneticresonance imaging. The instrument may be attached to other guided accessinstruments such as those described herein.

In yet another embodiment, a tibial attachment instrument is provided.The instrument comprises an elongate shaft extending at one end into aproximal end plate and at an opposite end into a distal end plate, eachof said plates including one or more holes for receiving a fixationelement, the distal end plate further including a notched tab forreceiving a guided access component.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosure. Additional features of thedisclosure will be set forth in part in the description which follows ormay be learned by practice of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of thedisclosure and together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 is a perspective view of an exemplary embodiment of a guide frameof the present disclosure.

FIG. 2 is a perspective view of an exemplary embodiment of an alignmentarm of the present disclosure.

FIG. 3 is a perspective view of an exemplary embodiment of a referenceguide ring of the present disclosure.

FIG. 4 shows an exemplary embodiment of a guide or navigation instrumentof the present disclosure positioned relative to an ankle joint.

FIG. 5 shows a perspective side view of the guide instrument of FIG. 4aligned to a talar bone.

FIG. 6 shows the guide instrument of FIG. 5 fixed to the anteriorportion of the tibia.

FIG. 7 shows the guide frame of FIG. 6 alone, attached to the tibia.

FIG. 8 shows the guide frame of FIG. 7 with the guide ring of FIG. 3.

FIG. 9 shows various trajectory paths along the guide ring of FIG. 3.

FIG. 10 shows pins inserted through the openings along the trajectorypaths of FIG. 9 of the guide ring.

FIG. 11 shows a partial exposed view of the various trajectory paths andinserted pins of FIGS. 9 and 10 relative to a talus.

FIG. 12 shows a partial exposed view of the inserted pins and guide ringof FIG. 10 relative to a talus.

FIGS. 13-15 illustrate different MRI templates of various trajectorypaths and focal points for insertion of instruments or devices relativeto a foot using another exemplary embodiment of a guide instrument ofthe present disclosure, in which FIG. 13 represents an axialperspective, FIG. 14 represents an oblique perspective, and FIG. 15represents a lateral perspective.

FIG. 16 is a perspective view of another exemplary embodiment of a guideinstrument of the present disclosure.

FIG. 17 shows the guide instrument of FIG. 16 with a fixation pin.

FIG. 18 shows the guide instrument and fixation pin of FIG. 17 in use ona talus of an ankle joint.

FIG. 19 shows the guide instrument of FIG. 16 with optional trajectorypaths for insertion of an instrument into the talus.

FIG. 20 illustrates a side view of yet another exemplary embodiment of aguide instrument of the present disclosure.

FIG. 21 illustrates a top-down view of the guide instrument of FIG. 20.

FIG. 22 illustrates a perspective view of the guide instrument of FIG.20 with optional trajectory paths for insertion of an instrument.

FIG. 23 shows the guide instrument of FIG. 20 in use with an anklejoint.

FIGS. 24-27 illustrate an exemplary method of using the guide instrumentof FIG. 20 to treat an ankle joint.

FIG. 28 illustrates a perspective view of an exemplary embodiment of afoot stabilizer and guided access instrument of the present disclosure.

FIG. 29 illustrates another perspective view of the foot stabilizer ofFIG. 28.

FIG. 30 illustrates an enlarged view of the guide component of the footstabilizer and guided access instrument of FIG. 28.

FIG. 31 shows a side view of the foot stabilizer and guided accessinstrument of FIG. 28 in use with a foot.

FIG. 32 is a perspective view of still another exemplary embodiment of afoot stabilizer and guided access instrument of the present disclosure.

FIG. 33 is a side view of the foot stabilizer and guided accessinstrument of FIG. 32.

FIG. 34 is a perspective view of an exemplary embodiment of an ankleprobe of the present disclosure in use on a foot.

FIGS. 35 and 36 are enlarged perspective views of the ankle probe ofFIG. 34 in use with a foot.

FIG. 37 is a perspective view of even still another exemplary embodimentof a foot stabilizer and guided access instrument of the presentdisclosure.

FIGS. 38 and 39 illustrate perspective views of an exemplary embodimentof a tibial attachment instrument of the present disclosure in use witha tibial bone.

FIG. 40 is an enlarged view of the tibial attachment instrument of FIGS.38 and 39 in use with a tibial bone.

FIGS. 41-44 illustrate exemplary methods of treating a subchondraldefect of an ankle joint by targeting different access points, in whichFIG. 41 shows treatment through the talus bone, FIG. 42 shows treatmentthrough the calcaneous bone, and FIGS. 43 and 44 show treatment throughthe tibia bone.

DESCRIPTION OF THE EMBODIMENTS

The present disclosure provides methodologies, devices and instrumentsfor diagnosing and treating joint pain to restore natural joint functionand preserving, as much as possible, the joint's articular and cartilagesurface. Treatments through the joint that violate the articular andcartilage surface often weaken the bone and have unpredictable results.Rather than focusing on treatment of pain through the joint, alternativetreatments that diagnose and treat pain at its source in the subchondralregion of a bone of a joint to relieve the pain are provided. Painassociated with joints, especially osteoarthritic joints, can becorrelated to bone defects or changes at the subchondral level ratherthan, for example, the severity of osteoarthritic progression or defectsat the articular surface level. In particular, bone defects, such asbone marrow lesions, edema, fissures, fractures, hardened bone, etc.near the joint surface lead to a mechanical disadvantage and abnormalstress distribution in the periarticular bone, which may causeinflammation and generate pain. By altering the makeup of theperiarticular bone (which may or may not be sclerotic) in relation tothe surrounding region, it is possible to change the structuralintegrity of the affected bone and restore normal healing function, thusleading to a resolution of the inflammation surrounding the defect.

Treatment of the bone by mechanical and biological means to restore thenormal physiologic stress distribution, and restore the healing balanceof the bone tissue at the subchondral level, is a more effect way oftreating pain than conventional techniques. That is, treatment can beeffectively achieved by mechanically strengthening or stabilizing thedefect, and biologically initiating or stimulating a healing response tothe defect. Methods, devices, and systems for a subchondral procedurethat achieve these goals are disclosed in co-owned U.S. Pat. No.8,062,364 entitled “OSTEOARTHRITIS TREATMENT AND DEVICE” as well as inco-owned and co-pending U.S. Patent Application Publication Nos.2011/0125156 entitled “METHOD FOR TREATING JOINT PAIN AND ASSOCIATEDINSTRUMENTS” and 2011/0125157 entitled “SUBCHONDRAL TREATMENT OF JOINTPAIN,” both of which were filed on Nov. 19, 2010, the contents of whichare incorporated by reference in their entirety. This subchondralprocedure, and its associated devices, instruments, etc. are alsomarketed under the registered trademark name of SUBCHONDROPLASTY™. TheSUBCHONDROPLASTY™ procedure is a response to a desire for an alternativeto patients facing partial or total joint replacement.

In general, the SUBCHONDROPLASTY™ or SCP™ technique is intended to bothstrengthen the bone and stimulate the bone. In SCP™, bone fractures ornon-unions are stabilized, integrated or healed, which results inreduction of a bone defect, such as a bone marrow lesion or edema. Inaddition, SCP™ restores or alters the distribution of forces in a jointto thereby relieve pain. SCP™ can be performed arthroscopically orpercutaneously to treat pain by stabilizing chronic stress fracture,resolving any chronic bone marrow lesion or edema, and preserving, asmuch as possible, the articular surfaces of the joint. SUBCHONDROPLASTY™generally comprises evaluating a joint, for example, by taking an imageof the joint, detecting the presence of one or more subchondral defects,diagnosing, which of these subchondral defects is the source of pain,and determining an extent of treatment for the subchondral defect. Thetechnique is particularly suited for treating chronic defects orinjuries, where the patient's natural healing response has not resolvedthe defect. It should be noted, however, that the technique is equallyapplicable to treatment of defects in the subchondral region of bonewhere the defect is due to an acute injury or from other violations.Several exemplary treatment modalities for SCP™ for the differentextents of treatment needed can be employed. Accordingly, a medicalpractitioner may elect to use the techniques and devices describedherein to subchondrally treat any number of bone defects, as he deemsappropriate.

Detection and identification of the relevant bone marrow lesion or bonemarrow edema (BML or BME) can be achieved by imaging, e.g., magneticresonance imaging (MRI), X-ray, bone scans, manual palpation, chemicalor biological assay, and the like. A T1-weighted MRI can be used todetect sclerotic bone, for example. Another example is that aT2-weighted MRI can be used to detect lesions, edemas, and cysts. X-rayimaging may be suitable for early-stage as well as end-stage arthritis.From the imaging, certain defects may be identified as the source ofpain. In general, defects that are associated with chronic injury andchronic deficit of healing are differentiated from defects that result,e.g., from diminished bone density. SCP™ treatments are appropriate fora BML or BME that may be characterized as a bone defect that ischronically unable to heal (or remodel) itself, which may cause anon-union of the bone, stress or insufficiency fractures, andperceptible pain. Factors considered may include, among other things,the nature of the defect, size of the defect, location of the defect,etc. For example, bone defects at the edge near the articular surface ofperiphery of a joint may be often considered eligible for treatment dueto edge-loading effects as well as the likelihood of bone hardening atthese locations. A bone defect caused by an acute injury would generallybe able to heal itself through the patient's own natural healingprocess. However, in such situations where the bone defect is due to anacute injury and either the defect does not heal on its own, or themedical practitioner decides that the present technique is appropriate,SCP™ treatment can be administered on acute stress fractures, BML orBME, or other subchondral defects, as previously mentioned.

The SCP™ treatment may continue after surgery. In particular, thepatient may be monitored for a change in pain scores, or positive changein function. For example, patients are also checked to see when they areable to perform full weight-bearing activity and when they can return tonormal activity. Of note, the SCP™ procedure can be revised and thusallows for optional further treatment in the event that a patientrequires or desires a joint replacement or other type of procedure. Theprocedure does not exclude a future joint repair or replacementtreatment to be applied, and thus may also be performed in conjunctionwith other procedures, such as cartilage resurfacing, regeneration orreplacement, if desired. In those instances where additional treatmentis desired, the SCP™ treated area may remain undisturbed while theadditional treatment is performed, such as where cartilage resurfacingis desired. Alternatively, the SCP™ treated area can be removed, and notcreate an obstacle to the additional treatment, such as where a partialor total joint replacement is desired. Advantageously, the SCP™treatment may be provided as a first or initial treatment, reserving forthe future and possibly forestalling until a later date than otherwisemight be the case more invasive treatments such as partial or totaljoint replacement.

A number of treatment modalities, and associated devices, instrumentsand related methods of use for performing SUBCHONDROPLASTY™ aredisclosed in the aforementioned publications. These treatment modalitiesmay be used alone or in combination.

In one treatment modality, the subchondral bone in the region of thebone marrow lesion or defect can be strengthened by introduction of ahardening material, such as a bone substitute, at the site. The bonesubstitute may be an injectable calcium phosphate ensconced in anoptimized carrier material. In SCP™, the injected material may alsoserve as a bone stimulator that reinvigorates the desired acute bonehealing activity.

For example, polymethylmethacrylate (PMMA) or calcium phosphate (CaP)cement injections can be made at the defect site. PMMA injection mayincrease the mechanical strength of the bone, allowing it to withstandgreater mechanical stresses. CaP cement injection may also increase themechanical strength of the bone, while also stimulating the localizedregion for bone fracture repair. In one embodiment, the injection can bemade parallel to the joint surface. In another embodiment, the injectioncan be made at an angle to the joint surface. In yet another embodiment,the injection can be made below a bone marrow lesion. Preferably, theinjection is made without disrupting the joint surface.

In another treatment modality, the subchondral bone region can bestimulated to trigger or improve the body's natural healing process. Forexample, in one embodiment of this treatment modality, one or more smallholes may be drilled at the region of the defect to increase stimulation(e.g., blood flow, cellular turnover, etc.) and initiate a healingresponse leading to bone repair. In another embodiment, after holes aredrilled an osteogenic, osteoinductive, or osteoconductive agent may beintroduced to the site. Bone graft material, for example, may be used tofill the hole. This treatment modality may create a betterload-supporting environment leading to long term healing. Electrical orheat stimulation may also be employed to stimulate the healing processof a chronically injured bone. Chemical, biochemical and/or biologicalstimulation may also be employed in SCP™. For instance, stimulation ofbone tissue in SCP™ may be enhanced via the use of cytokines and othercell signaling agents to trigger osteogenesis, chondrogenesis, and/orangiogenesis to perhaps reverse progression of osteoarthritis.

In yet another treatment modality, an implantable device may beimplanted into the subchondral bone to provide mechanical support to thedamaged or affected bone region, such as where an insufficiency fractureor stress fracture has occurred. The implant may help create a betterload distribution in the subchondral region. In load-bearing joints, theimplant may support compressive loads. In addition, the implant maymechanically integrate sclerotic bone with the surrounding healthy bonetissue. The implants may be place in cancellous bone, through scleroticbone, or under sclerotic bone at the affected bone region. The implantmay also be configured as a bi-cortical bone implant. In one embodiment,one side of the implant can be anchored to the peripheral cortex tocreate a cantilever beam support (i.e., a portion of the implant isinserted into bone but the second end stays outside or near the outersurface of the bone). The implant may be inserted using a guide wire. Inone example, the implant may be inserted over a guide wire. In anotherexample, the implant may be delivered through a guide instrument.

The implant may further be augmented with a PMMA or CaP cementinjection, other biologic agent, or an osteoconductive, osteoinductiveand/or osteogenic agent. The augmentation material may be introducedthrough the implant, around the implant, and/or apart from the implantbut at the affected bone region, such as into the lower region of a bonemarrow lesion or below the lesion. For example, the implant may act as aportal to inject the augmentation material into the subchondral boneregion.

While each of the above-mentioned treatment modalities may beadministered independent of one another, it is contemplated that anycombination of these modalities may be applied together and in any orderso desired, depending on the severity or stage of development of thebone defect(s). Suitable implantable fixation devices for the surgicaltreatment of these altered bone regions or bone defects, especially atthe subchondral level, are disclosed in co-pending and co-owned U.S.Patent Application Publication No. 2011/0125265 entitled “IMPLANTABLEDEVICES FOR SUBCHONDRAL TREATMENT OF JOINT PAIN,” U.S. PatentApplication Publication No. 2011/0125264 entitled “IMPLANTABLE DEVICESFOR SUBCHONDRAL TREATMENT OF JOINT PAIN,” and U.S. Patent ApplicationPublication No. 2011/0125272 entitled “BONE-DERIVED IMPLANTABLE DEVICESFOR SUBCHONDRAL TREATMENT OF JOINT PAIN,” all of which were filed onNov. 19, 2010, the contents of which are herein incorporated in theirentirety by reference. These devices and instruments can be use incombination with cements or hardening materials commonly used to repairdamaged bone by their introduction into or near the site of damage,either to create a binding agent, cellular scaffold or mechanicalscaffold for immobilization, regeneration or remodeling of the bonetissue. As previously stated, treatment of the bone defect at thesubchondral level preferably is performed without disrupting the jointsurface.

In general, the present disclosure provides embodiments related toinstruments and associated methods for the surgical treatment of a smalljoint, and particularly to a bone defect at that small joint region.More specifically, the embodiments relate to instruments for navigatingand positioning devices into an area sufficiently near a defect of thesmall joint. Even more specifically, the instruments and associatedmethods for use are suitable for the repair of the small joint, such asan ankle, elbow, wrist, or even shoulder joint. These instruments anddevices may be used in a manner consistent with the subchondralprocedures previously described.

In a healthy joint, the compressive load between the contact bones isproperly distributed, thus keeping the contact stresses in the cartilageto a reasonably low level. As the cartilage starts to wear out ordegenerate locally, the contact area reduces and starts to get localizedat the site of the cartilage defect. The localization of the stressesmay also occur due to varus or valgus deformity. Sometimes, thecondition may occur because of osteoporosis, where bone becomes weak andis no longer able to support normal loads. This condition leads tohigher localized contact stresses in the cartilage, and the subchondralregion below the cartilage. Once the stresses reach beyond a certainthreshold level, it leads to defects like bone marrow lesions and edema,and perhaps generates joint pain. If the problem persists, the highcontact stresses can lead to sclerotic bone formation as well. Thepresence of sclerotic bone can compromise vascularization of the localarea, and also create a mechanical mismatch in the bone tissue. Thismismatch may start to expedite degeneration of all parts of the jointleading to increased levels of osteoarthritis.

Pain associated with osteoarthritic joints can be correlated to bonedefects or changes at the subchondral level. In particular, bone defectssuch as bone marrow lesions, edema, fissures, fractures, etc. near thejoint surface lead to abnormal stress distribution in the periarticularbone, which may or may not cause inflammation and generate pain. Byaltering the makeup of the periarticular bone (which may or may not besclerotic) in relation to the surrounding region, it is possible tochange the structural integrity of the affected bone, leading to aresolution of the inflammation. Treatment of the bone in an effort toalter the structural makeup of the affected periarticular bone leads toreduced inflammation and pain has proven to be successful. Over time,normal physiologic stress distribution can be achieved, and mechanicalcongruity restored, thereby resulting in healing of the inflammation andreduction or elimination of pain. The same type of pathology appears innon-load bearing joints such as the wrist, elbow or shoulder joints, sothe treatment modalities described herein are equally applicable toosteoarthritic wrist, elbow or shoulder joints as well.

As previously mentioned, there is a need for surgical instruments thatwill facilitate the application of the methodologies described above atthe target site, or the bone defect, to be treated. Applicants havediscovered instruments that are particularly suitable for accessingcertain areas of the bone within the range of about 2-15 mm from thebone surface, and more commonly about 5-10 mm from the bone surface,such as the articular surface or the subchondral bone area, andtherefore require more precise defect location features. Theseinstruments are also particularly suited to deliver bone substitutematerial, devices, implants, etc. without disrupting the joint surface.Accordingly, the present disclosure provides suitable instruments andassociated methods for the surgical treatment of these bone defects,especially at the subchondral level near sclerotic bone.

As previously mentioned, there is a need for surgical instruments thatwill facilitate the application of the methodologies described above atthe target site, or the bone defect, to be treated. Particularlydesirable are instruments that allow for the application of themethodologies just described for small joints, such as the ankle joint.Accordingly, the present disclosure provides suitable instruments anddevices, and associated methods, for the surgical treatment of thesebone defects, especially at the subchondral level near sclerotic bone ofthese small joints.

In general, the present disclosure provides devices, instruments andassociated methods for the subchondral treatment of osteoarthritis insmall joints. For example, these small joints may be ankle, wrist,elbow, or even shoulder joints. Accordingly, embodiments of the presentdisclosure may be explained and illustrated with reference to treatmentof a patient's ankle joint. It is, of course, understood that theconcepts described herein apply equally to other small joints, such asthe elbow, wrist or even shoulder joint.

Turning now to the drawings, FIGS. 1 to 3 illustrate various componentsof a guide or navigation instrument 20, usable with the ankle joint 10as shown in FIG. 4. FIG. 1 shows a guide frame 40A comprising a mainbody 42 having an elongate slot 44 and a notched tab 46 for receiving adetachable alignment bar 40B, as shown in FIG. 2. The main body 42 alsocomprises a plurality of openings 48 for the insertion of fixationdevices to secure the guide frame 40A to a bone. The alignment bar 40Bincludes a main body 50 extending into a notched arm 52 that isconfigured to be received in the notched tab 46 of the guide frame 40A.The main body 50 also extends into a side arm 54, as shown.

In use, the guide frame and bar 40A, 40B may be attached together toform a tibial fixation assembly 40 and placed relative to an ankle joint10 to be treated, as illustrated in FIGS. 4 and 5. The fixation assembly40 may be aligned to the dome of the talus 12, as shown, or any otherdesired anatomical landmark. Once properly positioned, the guide framemay be fixed to the tibia 14 with pins 2. These pins 2 may be placedthrough the elongate slot 44 of the main body 42 of the guide 40A, atany point along its length, or through one of the openings 48, asfurther shown in FIGS. 6 and 7.

After fixing the fixation assembly 40 to the anterior portion of thetibia 14, the detachable alignment bar 40B may be removed, leaving theguide frame 40A remaining and fixed to the tibial bone 14, as shown inFIG. 7. Next, a reference guide ring 60 (FIG. 3) may be placed onto theguide frame 40A, as shown in FIG. 8. The guide ring 60 may comprise amain body 62 from which extends a notched arm 66 for attachment to thenotched tab 46 of the guide frame 40A. Attached to the main body 62 is apositioning arm 64 that contains a plurality of openings 68.

The openings 68 on the positioning arm provide entry points for aninstrument or device into the ankle joint 10, and in particular to thesubchondral region of the talus bone 12 of the ankle joint 10. Theseopenings 68 may represent common entry points for a minimally invasivetreatment of the talus 12. Of course, for any given plane or angle ofinsertion desired for entry into the talus 12, the present guide framesystem 20 allows for adjustment or settings for the angle of approachbased on the surgeon's preference. The openings 68 are each configuredwith a specific trajectory to allow the same length or depth pin to beinserted through a plurality of these openings 68 and target through adesired surgical entry focal point into the talus bone 12, allowing theability to pinpoint any defect at different anatomical locations insidethe talus 12. Surgical access to the talus 12 can be difficult andlimited due to the surrounding complexity of tissues including criticalnerves, tendons, ligaments, arteries, veins, and articulating jointsurfaces. In order to avoid damage to these surrounding tissues,surgical treatment to the talus 12 is limited to access paths through asmall number of focal areas. Thus, the trajectories though openings 68in the device provide for access to many internal points in the talus 12through a focal surgical access entry point at a location set to avoiddamage to surrounding tissues.

A map of corresponding injection areas can be created by approaching thetalus bone 12 through these multiple openings 68 provided on the guidering 60, and in a minimally invasive manner. The map of thesetrajectories can correspond to a MRI or other anatomical template usedin surgical planning to determine the specific trajectory needed totarget the location of the lesion as seen in the MRI. These openings 68may be sized and shape to allow the insertion of an instrument, deviceor both, in accordance with the treatment methods just described fortreating a subchondral defect of the ankle joint 10. These openings 68could, of course, also be configured to receive fixation pins 2 asshown.

FIGS. 9-12 illustrate the concept previously describe regarding themultiple trajectories or access paths to the talus 12. For example, FIG.9 shows various trajectory paths along the guide ring 60 via theopenings 68 (e.g, lines A-A, B-B, C-C, and D-D all converge at aspecific focal point, as shown). FIG. 10 shows fixation pins 2 insertedthrough the openings 68 along these trajectory paths relative to a talus12. FIG. 11 shows fixation pins 2 inserted through select openings 68 ofthe guide ring 60 and extending along select trajectory paths,converging and diverging through a common focal entry point, relative tothe talus 12. FIG. 12 shows a plurality of inserted pins 2 throughopenings 68 of the guide ring 60 relative to the talus 12. As FIGS. 9-12illustrate, there are many possible trajectories for the pin 2 or pins 2to reach different areas of the talus 12 to treat a subchondral defectin the manner previously described. Thus, the guide ring 60 is capableof directing a constant depth pin 2 or a plurality of pins 2 to specificlocations that can be mapped on a template, if so desired.

FIGS. 13-15 illustrate different MRI templates showing varioustrajectory paths and focal points for insertion of instruments ordevices using another exemplary embodiment of a guide instrument 80 ofthe present disclosure, in which FIG. 13 represents an axialperspective, FIG. 14 represents an oblique perspective, and FIG. 15represents a lateral perspective. As shown in FIG. 16, the guideinstrument 80 may include a main body 82, a first lip or flange 84 onwhich are one or more openings 90 for receiving an instrument such as apin 2. The openings 90 may be point of reference guide holes, forexample. The main body 82 may also include a second lip or flange 86that also includes one or more openings 92 for receiving an instrumentsuch as a pin 2, as shown in FIG. 17. The openings 92 may be elongate,forming slots 92 that allow for infinite adjustability during insertionof the instrument or pin 2.

In addition, the main body 82 may be shaped generally like a wedge, asshown, and include visual markers 96 that act as trajectory markerguides. At one corner of the main body 82 there may be a projection fromwhich there is a third lip or flange 88. This third flange 88 may alsoinclude an opening 94 for receiving an instrument such as a pin 2. Thisopening 94 may represent a distal guide instrument hole for receiving apin 2 distally. Alternatively, this hole could serve as a trajectoryguide opening for placement of a pin 2 into the anterior neck region ofthe talus 12 subchondral to the articulation surface with the navicularbone of the foot.

The guide instrument 80 may be considered a pre-set angular guideinstrument with integrated depth control. The guide instrument 80 mayallow for discrete targeting and angular trajectories which intersect atthe same final depth, controlled pin placement, guidance and depth intothe talus 12 of the ankle joint 10, and the ability to choose aninfinite angle of insertion (via the insertion opening 92) which thenconverge through a common point on the guide instrument 80 forinstrument or pin guidance into the bone of the ankle joint 10. Thevisual markers 96 may be discrete markers on the instrument 80 thatcorrelate to available angular trajectories known. The guide instrument80 may be hand held and manually placed to the correct anatomicallocation or stabilized by fixing to a foot positioner or stabilizerthrough, for example, a swivel or rigid connection (e.g., thread, clamp,etc.) Alternatively, the instrument 80 could be positioned to afluoroscopic alignment bar that would locate the reference target point.

In one embodiment, the guide instrument 80 may be made of a radiolucentmaterial. The visual markers 96 may be radiopaque and embedded withinthe guide instrument 80 to help orient the guide instrument 80 toreference anatomical locations.

In one exemplary method of use, MRI templates similar to those of FIGS.13-15 may be used to locate a subchondral defect in a talus. Forinstance, a bone marrow lesion (BML) or bone marrow edema (BME) may belocated using an axial magnetic resonance image. From this, a tangencypoint of the talar dome slope may be located using lateral fluoroscopy.Next, the guide instrument 80 may be positioned relative to the anklejoint 10, wherein the instrument 80 may be placed at the target area tobe treated. The guide instrument 80 may be secured to the patientthrough, for example, attachment with a swivel arm attachment (notshown) or fixed with a pin 2 to the distal tibia or calcanaeus bone.

Once the guide instrument 80 has been secured, a pin 2 may be insertedinto the elongate slot or opening 90 on the first flange 84 and throughopening 92 of the second flange 86, until a desired depth is reached (asdetermined by markings 4 on the pin 2, for example, that indicate thatthe predetermined depth has been reached.) This step is illustrated inFIG. 18. After the pin 2 has been properly inserted, a cannula (notshown) may be placed over the pin 2, and the pin 2 removed to leave onlythe cannula within the opening 90. An injectable material, such as abone hardening material, may then be injected through the cannula andinto the talus 12 toward the subchondral defect to be treated. Theentire process may be repeated, using a different trajectory path, suchas one of those shown in shadow in FIG. 19.

Suitable injectable materials can include bone fillers, but are notlimited to materials comprising beta-tricalcium phosphate (e.g., VITOSS,PROOSTEON 500R made by E-Interpore-Cross International), hydroxyapatite(e.g., OSTEOGRAF made by Ceramed Denta, Inc., Lakewood, Colo.), calciumcarbonate, calcium sulfate (e.g., OSTEOSET and ALLOMATRIX made by WrightMedical Technology, Inc.), calcium phosphate (e.g., CALCIBON made byMerck & Co., Inc., Whitehouse Station, N.J. and NORIAN SRS made bySynthes-Strates, Switzerland), synthetic bone fillers (e.g., CORTOSS)and/or processed bone fillers (e.g., BIOOSS made by GeistlichBiomaterials, Inc., Switzerland). Other suitable materials may includehydrogels, PEEK (polyetheretherketone), carbon fiber, polycarbonateurethane (PCU), stem cells with and without matrices, collagen with andwithout matrices and carriers, pharmacotherapeutic with and withoutmatrices and carriers, hyaluronic acid with and without matrices, insitu curable materials with and without anti-inflammatory agents,demineralized bone matrix, allograft, biocompatible metals, resorbablePCA, PGLA, and polyurethane, hydroxyapatite, calcium sulfate, BMP growthfactor, TGF-β super family, MP52, TP508, bioactive glass, sodiumalignate, AOC based carrier and active components (synthetic beeswax),and starch.

FIGS. 20-22 illustrate yet another exemplary embodiment of a guideinstrument 100 of the present disclosure. As shown in FIG. 20, guideinstrument 100 may be used as a targeting device for locating, targetingand accessing the subchondral space of the talus, calcanaeus, or distaltibia. In one embodiment, the guide instrument 100 may be formed as apre-set angle guide. As shown in FIGS. 21 and 22, the guide instrument100 may comprise a main body 102 having a plurality of guide portals 108for guiding an instrument or pin 2 toward the target area of the anklejoint 10 to be treated. The guide portals 108 may be pre-set andconfigured as angled trajectory portals. These portals 108 may furtherbe spaced equally apart at a range of about 10-45 degrees, and representan array of angular trajectories (A₁-A₁, A₂-A₂, A₃-A₃, and A₄-A₄). Aswith the previously described embodiments, in order to avoid damage tosurrounding tissues, surgical treatment is limited to access pathsthrough a small number of focal areas represented by the portals 108.

The main body 102 may also include a tab 104 with a through-hole 106that allows the guide instrument 100 to connect to another equipment,such as for example, a foot positioner or stabilizer similar to the oneshown in FIGS. 28-31. The tab 104 thus allows for a swivel hingeconnection to be made with that foot positioner or stabilizer. Inaddition, the guide instrument 100 may include an alignment arm 110 thatextends from the main body 102 and orients the instrument 100 to thecorrect pitch, roll and yaw angles. In one embodiment, the alignment arm110 may have a flat planar configuration to indicate on fluoroscopy thatthe guide instrument 100 is correctly positioned (i.e., not rotated) byindication of a thin line versus a thick rectangular band.

The guide instrument 100 allows the user to control the angle ofrotation in three dimensions with the pre-set angled trajectory or guideportals 108 on the main body 102. The alignment arm 110 indicates heightand sagittal angulation of the portals 108, while the ability to swivelthe instrument 100 via the swivel hinge attachment to the footstabilizer allows for both transverse and sagittal angulation to thedesired target point on the ankle joint 10. A pin can be placed into oneof the guide portals 108 to help verify transverse and sagittalangulation or orientation relative to the talus or calcaneous bone underfluoroscopic imaging.

FIGS. 23-27 show one exemplary method of using the guide instrument 100.First, the guide instrument 100 may be aligned to the dome of the talus12, as shown in FIG. 23. The guide instrument 100 allows an instrument,such as a fixation element like a pin 2, may be inserted through one ofthe portals 108 of the guide instrument 100, as shown in FIG. 24. Theguide instrument 100 may then be aligned height-wise, such as to theheight of the talar dome subchondral defect (e.g., lesion or edema), asshown in FIG. 25. Then, the guide instrument 100 may be aligned toreference points P₁ and P₂ on the talar dome, where P₁ and P₂ representpoints along a line of tangency, for example (FIG. 26). After alignment,the guide instrument 100 provides guided access of an instrument or pin2 through one of the pre-set angled portals 108 and to the targetlocation of the ankle joint 10 to be treated, as shown in FIG. 27.Limiting the surgeon's access paths to the bone to the few select focalareas represented by the pre-set angled portals 108 avoids undesired oraccidental damage to surrounding tissues.

FIGS. 28 and 29 illustrate an exemplary embodiment of a foot stabilizerand guided access instrument 200 of the present disclosure. The footstabilizer and guided access instrument 200 includes a platform 202 thatmay be secured to the foot to be treated using ties, bands, straps,Velcro, belts, suspenders, etc. as may be commonly employed in the art.The guidance instruments previously described and shown, as well asother navigation or guidance instruments for guided access into a joint,may be coupled to the foot stabilizer and guided access instrument 200.In one embodiment, the foot stabilizer and guided access instrument 200may be provided with its own guided access component 210, as shown inFIG. 29. This guided access component 210 may be adjustable (i.e.,mobile) until it is locked or fixed into position.

It is contemplated that this foot stabilizer and guided accessinstrument 200 be adjustable in length as well as width, and be rigidlysecured to a foot with the securing elements just described. Of course,it is also contemplated that the foot stabilizer and guided accessinstrument 200 could be provided with a built-in foot attachment system,such as for example, a crank similar to those in ski boots, or anet-like band of Velcro such as found in sandals, so long as theattachment system does not impede in the access to be desired. While thefoot stabilizer and guided access instrument 200 may be entirely rigid,it is also possible for the instrument 200 to be rigid in part. Andalthough the platform 202 of the foot stabilizer and guided accessinstrument 200 is shown here as having a relatively flat surface, it isof course contemplated that the platform 202 could also have a contouredsurface to match the foot more anatomically and provide a better fit. Itis also contemplated that the foot stabilizer could have an extensionthat secures to the back of the calf of the leg using securing elementsas previously mentioned above. With this extension, the device couldsecure the angular position of the foot relative to the lower leg ortibia in order to provide more accurate controlled access to the ankle.

Turning now to FIG. 29 and to the details of the foot stabilizer andguided access instrument 200, the foot stabilizer and guided accessinstrument 200 may include a pair of tracks 204 extending from theplatform 202, each track 204 having a slotted rail 206 for translationalmovement of an attachment arm 212. The tracks 204 allow the user toplace this arm 212 on either the left or right side of the footstabilizer 200. The arm 212 may be attached to the track 204 with a cam214, as shown. Attached to the arm is an adjustable guided accesscomponent 210 that may be fixed into position to allow guided access ofan instrument or pin 2 into the bone of the foot to be treated. In otherembodiments, the guided access component 210 and arm 212 may be fixed tothe platform 202 with screws or other known fixation elements, so longas the arm 212 remains securely attached to the platform 202 of the footstabilizer 200.

As shown in greater detail in FIG. 30, the guided access component 210may include a main body 220 from which extends a visualization bar 224.The visualization bar 224 serves as a fluoroscopic visual marker thatallows the user to align the instrument to anatomical markers underfluoroscopy. The body 220 also includes a pivotable hub 228 from whichextends a portal 226 that serves as a guided access path for aninstrument or pin 2 to be inserted therethrough. This pivotable hub 228is rotatable within a slot of the body 220. As illustrated, thepivotable hub 228 may include divots 230 that may work with a ballplunger inside the mail body 220 to provide an adjustable stop orcontrol mechanism for alignment of the portal 226. The pivotable hub 228may thus click into a desired position. For instance, the divots 230could allow positioning of the portal 226 to direct the trajectory pathof the pin 2 toward selected points on the bone to be treated. Thedivots 230 also may limit the path of approach, preventing dangerousapproaches to the bone. Pinned slots provided on the body 220 wouldcooperate with the pivotable hub 228 to prevent over-rotation. Theguided access component 210 may be secured to the attachment arm 212with a threaded mechanism such as with knob 240 as shown.

During use, the arm 212 may be shifted along the slotted rail 206 in atranslational direction, but could also pivot as well. The attachmentarm 212 may be secured to the track 204 with the cam 214. The portal 226can be configured as a tube having a length and overall geometric shapethat is suitable to support a pin 2, without bending and skiving of thepin 2 during use, as shown in FIG. 31. The ability to adjust theattachment arm 212 as well as the guided access component 210 relativeto one another as well as to the platform 202 allows the user greaterflexibility in aligning the portal 226 in any number of configurations.Thus, the foot stabilizer and guided access instrument 200 may be usefulfor targeting a number of locations on or near the foot, such as thetalus, tibia, fibula, calcaneous, etc.

FIGS. 32 and 33 illustrate another exemplary embodiment of a footstabilizer and guided access instrument 300 of the present invention. Asshown the instrument 300 may comprise a foot stabilizing component 310and a guided access component 320. The foot stabilizing component 310may include a platform 312 attached to which is a foot band 314 thatsurrounds a portion of the patient's foot. The foot band 314 may beunitary or it may be formed in portions. The guided access component 320comprises a bar 322 that attaches to the foot band 314 by way of athreaded connection, such as for example, knob 318 as shown. The bar 322extends into grid panels 324 on which are a plurality of openings orportals 326 for guiding an instrument or pin 2 therethrough. The gridpanels 324 may also include visualization aids, such as for examplefluoroscopic markers 330.

In use, the patient's foot may be secured to the foot stabilizingcomponent by means of the foot band 314, which could be ties, straps,bands, belts, etc. as previously described. The grid panels 324 arerotated so as to be aligned when the foot is in a true lateral position.The alignment may be achieved using the fluoroscopic markers 330provided on the grid panels 324. For instance, the markers 330 may beconfigured to overlap when the foot is in the true lateral position. Theguided access component 320 may be rotated relative to the footstabilizing component 310 and then fixed into place with the knob 318.The openings or portals 326 would allow access to multiple bones, foradditional flexibility during surgery.

FIGS. 34-36 illustrate an exemplary ankle probe 400 of the presentdisclosure. The ankle probe 400 is intended to rest between the talus 12and the distal tibia 14, as shown. The ankle probe 400 is configured toallow more direct contact with bone on either the left or right side ofthe ankle joint 10 to control horizontal positioning. At least some orall of the ankle probe 400 may be made with radiopaque material to bevisualized under fluoroscopy. Additionally, the ankle probe 400 mayinclude a hole or other visual indicator to allow the user to verifythat it is in a true lateral position relative to bone.

As shown, the ankle probe 400 comprises a handle 402 that extends into apair of legs 404. One of the legs 404 terminates into a foot rest orbone rest 410. As shown in FIG. 35, the rest 410 may be contoured andconfigured to rest against the talus 12. The rest 410 may be angularlyadjustable relative to the leg 404 for ease of use. In one embodiment,the rest 410 may include an alignment hole 412 that would show up whenthe probe 400 is in true lateral position. The alignment hole 412 mayalso be placed so as to correspond to the bone (e.g., bottom of talardome), allowing for alignment with an anatomical landmark.

The other leg 404 may be attached to a guide body 420 by way of aslotted receiver 426. This allows for easy removal of the guide body 420from the handle 402 without affecting a pin 2 that has been insertedtherethrough. The guide body 420 may include a platform 422 on which isprovided a plurality of portals 424 for guided access of a pin 2 orother instrument to a region of the ankle joint 10. The portals 424 maybe angularly pre-set so that the portals 424 target specific locationsin the bone. Again, in order to avoid damage to surrounding tissues,surgical treatment is limited to access paths through a small number offocal areas represented by the portals 424. The handle 402 allows forcontrol of the probe 400 and keeps the user's hand away from any C-armshots that may be needed during surgery.

FIG. 36 illustrates another embodiment of the ankle probe 400 in whichthe handle 432 and the first leg 434 is straight, taking the shape of aT-bar, while the other leg is curved into a sweeping arm 436. Thestraight leg 434 may terminate into a foot 438 that is configured torest on bone. The sweeping arm 436 may be configured to cooperate withthe guide body 420 by sliding engagement with the slotted receiver 426of the guide body 420. As shown, the ankle probe 400 may be positionedbetween the talus 12 and the tibia 14, resting against the fibula. It iscontemplated, however, that the probe 400 could also be positionedadjacent to the malleolus with a differently shaped sweeping arm forlateral approaches. Various configurations are contemplated in which thehandle or guide may be different to address any of the bones of theankle joint 10.

FIG. 37 illustrates an exemplary embodiment of still another footstabilizer and guided access instrument 500 of the present disclosure.The instrument 500 may be configured to secure the foot to be treatedduring an MRI. Thus the instrument 500 may be made of a material that isvisible on MRI. As shown, the instrument 500 shares similar features tothe previously described foot stabilizer and guided access instruments,such as a platform 502 from which extends at least one track 510. Thetrack may include a slotted rail 512 for attachment to other equipment,such as those already described above. These equipment may optionally beattached to the instrument 500 during the MRI, or they may be attachedafter the MRI visualization, and marked to be mapped to the MRI.Extending from the platform 502 is a boot 504 containing a plurality ofportals 506 for guided access to the ankle joint 10. The multipleopenings provided by the portals 506 allow for a variety of trajectoriesor approaches to the ankle joint 10 as well as for attachment to thetibia 14 or other bone.

In use, the exact approach of the instrument or pin 2 would bedetermined using MRI and viewing the relation between the subchondraldefect (BME or BML, for example) and the instrument 500. With thisinformation, the exact portal(s) 506 may be selected to achieve thedesired trajectory or path of insertion.

FIGS. 38-40 illustrate an exemplary embodiment of a tibial attachmentinstrument 600 of the present disclosure. This tibial attachmentinstrument 600 provides one manner of treatment by allowing the surgeonto target a different access point at or near the small joint. Theinstrument 600 is intended to attach to the tibia 14 and allow otherguides or instruments to then be secured to it as well. In this example,the distal tibial bone is targeted. Much like in a knee joint whereeither or both of the tibial and femur can be targeted for subchondraltreatment, the distal tibia and/or the talus or calcaneous bone may betargeted in ankle joint treatment.

As shown, the tibial attachment instrument 600 comprises an elongateshaft 602 that terminates into a proximal end plate 604 and a distal endplate 606, both plates having at least one hole 608 for receiving aninstrument such as a fixation element like a pin 2. In addition, thedistal end plate 606 includes a notched tab 610 to allow other guideinstruments and access instruments to attach to this tibial attachmentinstrument 600.

Although the instrument 600 is shown as being attached to the tibia 14with pins 2, it is contemplated that other known fixation elements maybe used, such as straps, belts, ties, etc. The instrument 600 provides asecure connection for other guides that target specific bones of theankle joint 10 to be attached to a stable construct. The elongate shaft602 is configured to span a substantial length of the tibia 14 whilebeing secured to the bone at the proximal and distal ends. The notchedtab 610 allows the other guides and instruments to be adjustablyattached to the instrument 600, such as by a detachable interferencefit. However, other fixation mechanisms may also be employed, such as aball plunger, cam or set screw.

In another embodiment, the elongate shaft 602 may be curved to match acontour of the tibial bone 14. The shaft 602 may be made of a radiopaquematerial to assist in positioning with fluoroscopy. In addition, theinstrument 600 may be provided with markers to match anatomicallandmarks for purposes of positioning and aligning the instrument 600.The tibial attachment instrument 600 allows individualized and precisealignment to a patient's natural anatomy, in turn allowing more accurateguide attachment and bone targeting.

FIGS. 41-44 illustrate exemplary methods of treating a subchondraldefect of an ankle joint 10 in accordance with the present disclosure.As previously discussed, one manner of treating pain associated withosteoarthritis of the ankle joint 10 is to identify and stabilize asubchondral defect in the bone of the small joint. Using any one of theguide or access instruments described herein, a surgeon may place a pin2 into a location at or near the subchondral defect of the bone, such asthe talus 12 of FIG. 41. A cannula 32 may be slid over the pin 2, andthe pin 2 removed to leave the cannula 32. Then, an injection systemcomprising a syringe 36, plunger 34 with associated handle 30 may beapplied to the cannula 32, as shown generally in FIGS. 41-44. Thesyringe 36 may include a bone hardening material, such as a bonesubstitute material or other material as described above. The materialmay be injected through the cannula 32 and through its ports 38 at itsdistal end, as shown in FIGS. 43 and 44, leaving the material inside thesubchondral region of the bone to stabilize the targeted defect.

As further illustrated, the exemplary treatment methods may be performedby targeting different access points at or near the small joint. Forexample, FIG. 41 shows treatment through access to the talus bone 12,while FIG. 42 shows treatment through access to the calcaneous bone.FIGS. 43 and 44 show treatment through the tibia bone 14. Again, similarto a knee joint where either or both of the tibial and femur can betargeted for subchondral treatment, the distal tibia and/or the talus orcalcaneous bone may be targeted in ankle joint treatment.

Finally, the treatments and instruments of the present disclosure may beapplied to other small joints like the wrist, elbow, or even shoulderjoint, in a similar manner as described and illustrated herein for anankle joint.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of thedisclosure provided herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the disclosure being indicated by the following claims.

What is claimed is:
 1. A method of subchondrally accessing a targeteddelivery site in a subchondral region of a talus bone of a patient, themethod comprising: identifying a subchondral defect in a subchondralregion of a talus bone of a patient, the talus bone including a curvedarticular surface for articulating with an articular surface of a distaltibia, the subchondral region of the talus bone occurring under thecurved articular surface; providing or obtaining a probe that includes ahandle extending into a first leg and a second leg, the first legincluding a bone rest at a first end of the first leg for restingagainst the curved articular surface of the talus bone, the second legincluding a guide body with at least a first opening extending throughthe guide body for receiving an access tool; positioning the bone restbetween the talus bone and the distal tibia so that the bone rest restsagainst the curved articular surface of the talus bone; and advancing anaccess tool through the first opening in the guide body and into thetalus bone to a targeted delivery site in or near the subchondral defectin the subchondral region of the talus bone.
 2. The method of claim 1further comprising injecting a bone filler into the targeted deliverysite.
 3. The method of claim 2, wherein the bone filler includes acalcium phosphate material.
 4. The method of claim 1, wherein thesubchondral defect is a bone marrow lesion.
 5. The method of claim 1further comprising removing the guide body from the second leg.
 6. Themethod of claim 1, wherein the bone rest is contoured to rest againstthe curved surface of the talus bone.
 7. The method of claim 1,conducted in a manner that preserves the curved articular surface of thetalus bone.
 8. The method of claim 1, wherein, with the bone restresting against the curved articular surface of the talus bone, thetargeted delivery site is spaced a distance from the bone rest.
 9. Themethod of claim 1 further comprising angularly adjusting the bone restat the first end of the first leg.
 10. The method of claim 1 furthercomprising visualizing a visualization marker of the probe to verifywhether the probe is in a true lateral position relative to the talusbone.
 11. The method of claim 10, wherein the visualization marker is avisualization hole in the probe.
 12. The method of claim 11, wherein thevisualization hole is in the bone rest.